Engineer s level-rod



(.NOMOdSL) M. L. LYNCH.

Engineers Level Rod.-

No.234,997. Patented Nov. 30,1880.-

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ATTORNEYS.

N.PETERS, P m-UTHOGRAF'NER, WASHINGTON. \Ivy 6.

UNITED STATES PATENT TTTTT @fir MICHAEL L. LYNCH, OF CAMERON, TEXAS.

ENGINEERS LEVEL-ROD.

SPECIFICATION forming part of Letters Patent No. 234,997, dated November 30, 1880,

Application filed September 18, 1880.

To all whom it may concern Be it known that I, MIcHAEL L. LYNCH, of Cameron, in the county of Milam and State of Texas, have invented a new and Improved Engineers Level-Rod; and I do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming part of this specification.

My invention relates to the class known as self-reading level-rods, and is distinguished from others by the peculiar manner of marking the scale upon the face of the rod, whereby the readings of fractions of a foot may be readily made without the use of a sliding target.

Heretofore such rods have been made showing the foot marks and intermediate onetenths of a foot by straight lines, each tenthmark in such case being numbered from 1 to 9, inclusive, which required of the engineer to judge or guess at the exact height above or below the nearest tenth-mark on the rod that the cross -wires in his instrument covered. Others, again,have been made with the one tenths of each foot subdivided by rectangular blocks of alternate black and white colors into spaces of one-hundredth of a foot each, but which in practice, from the confusion to the eye caused by so many small spaces, could not be read accurately beyond a short distance.

My invention consists in the peculiar form of the marks upon the face of the rod by which it is graduated, whereby the rod may be read with great accuracy to the one-hundredth part of a foot without'the employment of numerals to indicate the fractional. parts, as will hereinafter appear.

In the accompanying drawings, Figure 1 is a front elevation of a section of rod graduated according to my invention, and Fig. 2 a similar view of a smaller portion of the rod upon a larger scale.

The face of the rod is laid off to feet and tenths of a foot-by triangular or half-diamond shaped marks A A A the bases of which accurately measure the twentieth of a foot, a pair of which are arranged opposite each other along the entire length of the rod, the bases of which rest upon the outer edges of the rod, so that their apexes will touch each other at a (No model.)

point at equal distances from the sides of the rod, and so that ten spaces between the points so arranged will measure, and each apex will consequentlyindicate, the tenth of afoot from the apexes above and below it. The feet are indicated by the usual numerals, B, arranged across the apexes of each tenth graduation A and painted in red color upon awhite ground. Each of the graduations, excepting the fifth or half-foot graduation A midway between the foot-graduations, is painted in black upon a white ground, while the said intermediate or half-foot graduations A are painted in red,with a small diamondshaped figure, c of the same color arranged centrally between and overlapping the adjoining apexes of the said graduations.

In order that the rod may be read to fractions less than the tenth of a foot, the intermediate twentieth-of-a'foot spaces between the graduations A A A are all covered bysmaller triangular figures or graduations 0, all of which are painted in black upon the white ground, and the apexes of which are placed at a point but one-fourth of the distance across the face of the rod, so that a line drawn across their apeXes will fall midway between the onetenth graduations, by which means the rod may be read to the twentieth of a foot, and lines drawn across the face of the rod from the points where the ends of the bases of the small and the ends of the bases of the large figures meet will fall at equal distances from the onetwentieth graduation, or as represented by decimals, 0.05, and will therefore enable the rod to be read to the one-fortieth of a foot, or 0.025, while the one-hundredth, or 0.01, of a foot may bejudged by the eye.

The above measurements will be readily understood, as the bases of both the large figures A A A and the small figures G measure the twentieth of a foot, ten of each being required to measure a foot.

It will also be seen that as the points of each of the triangular figures will, if projected across the rod, fall at equal distances from the ends of the bases, the twentieth measurements will be subdividedintofortieths ofafoot.

The leading features of my design consist in the manner in which the graduations of each one-tenth of a foot and the subdivisions of the same are laid off on the rod, the peculiar pointed shape of the graduating figures enabling the operator at the instrument to determine with absolute accuracyeach one-tenth ot'a foot on the rod and each subdivision of two and one-half hundredths between each tenth, and with great accuracy each one-hundreth of a foot of space on the entire rod; also, from the peculiar manner in which the rod is graduated, it does away with the necessity of having the one-tenth marks numbered, as the graduating-mark for each half-foot is of a different shape from the others and painted in a different color, thus materially aiding the eye of the operator at the instrument in enabling him without loss of time to determine the correct elevation.

What I claim as new is leveling-rod provided with triangular fig ures arranged opposite each other upon the face of the rod, the apexcs of which meet midway across the face of the rod to indicate the one-tenth parts of a foot, and one in ten of which are marked by numerals to indicate the graduations representing feet, and the fifth or intermediate figures between the foot-graduations of a different color from the other figures, and formed with a diamond-shaped central portion, in the manner and for the purpose substantially as described.

MICHAEL L. LYNCH.

X Vitnesses:

W. D. FARISI-I, VICTOR SETLEY. 

